Automatic safety valve for pneumatic tires



Dec. 10, 1929.

D. E. WASHINGTON; 2-D

AUTOMATIC SAFETY VALVI FOR PNEUMATIC TIRES Filed April 25, 1927 INVENTORPatented ea. 10, 1929 mxoix'i E. WASHINGTON, 29,01 KANSAS CITY, inssooarAUTOMATIC SAFETY VALVE FOB ENEUM'ATIC {BIKES Application filed April 25,1927. Serial No. 186,239.

This invention relates to charging valves for pneumatic tires orthelike, and has for its primary object the provision of means forpermitting only a predetermined pressure to be built up inthe tire.

Another object of this invention is the provision of a device having coorating valves whereby the filling of the chamber with which, it is usedis done thru one ofthe said valves while the other said valve permits ofthe release of air in excess of the predetermined pressure. I

A further object of this invention is to provide a safety valve which isprovided with an audible signaling device which is operated by theexhausting airfrom the pneumatic tire.

A still further object of this invention is the'provision of a safetyvalve which is easily afiixed to the valve stem now in general use.

Many minor objects of the invention will appear during, the course ofthe detailed specification referring to the accompanying drawing, inwhich v Figure 1, is aside elevation of the safety valve showing thesame used in conjunction with an ordinary pneumatic tire and valve 7Fig.2, is a vertical central section on line Il[II of Fig. 1.

Fig. 3, is a cross-section on line III-III of Fig. 2.

- Fig. 4, is a similar cross-section on, line IVIV of Fig. 2.

Fig. 5, is a similar cross-section taken on line V-V of Fig. 2, and

Fig. 6 is a vertical central section of a modifired form of the valve. 1

Similar reference characters refer to like parts thruout the severalviews, and the numeral 6 designates a fragment of pneumatic tire, whichis equipped withthe ordinary valve stem' 7, to which may be attached thedevice-made in accordance with this'invention. Referring now to Fig. 2,which shows the general embodiment of this invention, 8 designates ahousing having plugs 9 and 10 at each end respectively thereof.- Theplug 9 having an integral inner tubularextension 12, extending axiallyand longitudinally of the housing 8 to join opposite plug 10. Plug 9, asshown in Fig. 2, has a tapped cavity 13 extending inwardly from theouter end, a which serves-as a means for afiixilig the device tothe'ordinary valve stem 7.

,In the use of this safety valve, the valve core ordinarily used in thewell known valve stem 7 is removed and a structure performing a similarfunction is provided in the attachable safety valve. tubular'portion 12communicates with cavity 13 of'the plug 9 and carries a valve stem 14,which extends therethru and is provided at one end with a valve 15whichseats on valve seat 16 .formed by the annular inner edge of 6 the tube12. Stem 14 extends thruand above plug 10 to be engaged by a tensionspring 17 which serves to hold valve 15 in closed rela-' tion to valve'seat 16. As clearly shown in Fig.

2, this tension spring17is held'in position m around the upper end ofvalve stem 14 by means of a cup washer 18, which in 'turn is held inposit-ion by head 19 formed on the upper end of valve stem 14.

To properly-perform the function desired of this invention, it isnecessary to provide a (lo-operating auxiliary valve which releases theair pressure when a predetermined fprs-' sure is reached. Accordingly,the preferred embodiment of this invention may provide anauxiliary-valve 20, which is 'slidably. mounted on tube 12. The lowerportion of auxiliary valve 20 has a depending annular flange 21, whichnormally seats on valvle seat 22. Valve seat 22 is located in an annu-.35 18.1 notch formed by'plug 9, thus permitting the upper end of plu 9.to extend within the confines of'the annu ar depending flange 21 whenthe auxiliary valve 20' is in the seated position. Plug 9 is providedwith-a plur'al-" ity of openings 23 which extend thru the upper endthereof to join cavity 13, and the space formed within the annular wallof the auxiliary valve 20 when in the closed posi tion. Thisconstruction permits of agreater operating surface for the air pressurethus rendering a more accurate operation pf the safety valve. I

Due to the fact that it is necessary to proi i vide valves to operateunder varying prede- 1'00 The above mentioned 5- one end of the spring24 bears against a shoulder 25 formed'at one end of auxiliary I valve20, while th'e'other end bears against theunder side of plug 10. Asshown in Fig; 2, the auxiliary valve extends upwardly along tube 12 'toform a substantial guide. The sliding fit'between the inner surface ofthis portion of auxiliary valve 20 and tube is claimed as new anddesired to be secured by Letters Patent is:

1. In a safety valve, a housing, upper and lower partitions in saidhousing, a tubular member connecting said partitions, said lowerpartition having inlet and outlet'air passages therein, valvesforclosing said passages, said upper. partition having air outlet portstherein and adapted to vent. the air passed through the outlet passagein the lower partition.

2. In a safety valve as set forth in claim 1, wherein the upperpartition is provided with an upwardly extending tubular portion,

, 5 to pass into the ,housing 8 and thence thru a said portion havingthreads on its outer periphery, a cap for engaging saidthreads, tweenthe two; said cap eing provided with means for clos- 1 When the chargingair passing into the ing the air outlet ports in said upper part1- & the6 thru tube 12,- cavity 13 and stem 7 rises I I a 20 above apredetermined pressure, air passes m ny O I hereunto aifiX my thru theopenings 12 in plug 9 and exerts a g lr pressure against auxiliaryvalve20, thus com- 1 DIXON E. WASHINGTON, II. pressing spring 2 l andlifting the auxiliary valve 20 from its seat 22, and permitting air 12is such that a perfect seal is maintained at 0 all times, and no airescapes upwardly be- 90 plurality of perforations 26 which are formed 1thru plug 10. When this operation takes place, the cap '27 has beenremoved and the constant escape of air thru perforations 26' will emitan audible signal which is the res'ultof the construction and size ofthe perforations'26. Plug'lO is formed with an outwardly extendingexternally threaded tubu-' L lar projection 28 which houses the upperend. as of stem 14 and spring 17, and cup washer 18. Cap 27 which isprovided with a gasket 29 is internally threaded to-fit the threadedportion of plug 10 'to seal the perforations 26 in plug 10, and alsoseals theupper end of pro- 40 jec'tion28.

The modified form of construction shown in Fig. 6 does not differ in thebasic prinia ple, but merely illustrates a different way of constructinga valve in accordance with this 5 invention. Practically all the partsare like those shown in Figs. 1 to 5 inclusive, with the 1 exception ofthe auxiliary valve structure.. In this instance, the'auxiliary valvehas a tapered head integral with the sleeve por-' 50 tion, which restsupbn the annular edge 51- "of the valve seat when in the closedposition. A chamber is formed below the auxiliaryvalve and around thecharging valve, tmel same 55 as in the preferred form of the invent'on.

The operation of this novel safety valve. has been made cleanthruout thespecification, and while the-preferred formis illustrated and described,it is to be understood that many modifications may be made and a greatvariance in the selection of materials practiced without departing fromthe scope of the ap pended claims and the spirit of the invention ingeneral.

65 Having thus described the invention, what

